A Luminescent Terbium MOF Containing Hydroxyl Groups Exhibits Selective Sensing of Nitroaromatic Compounds and Fe(III) Ions

A new 3D porous Tb(III)-ion based PMOF, {[Tb( L )(DMA)]·(DMA)·(0.5H 2 O)} ( 1 ) (where L = L 3–, H 3 L = 3′-hydroxybiphenyl-3,4′,5-tricarboxylic acid), with uncoordinated hydroxyl groups decorating the pores has been solvothermally synthesized in moderate yield. The hydroxyl groups act as potential interaction sites to sensitize the luminescence output of the Tb 3+ ion. Luminescence studies reveal that the PMOF can selectively and reversibly sense nitroaromatic compounds and Fe(III) ions in DMF suspension through fluorescence quenching observable under UV light. The probable mechanisms for such sensing processes are, for the nitroaromatic compounds, the host–guest interactions with the PMOF and, for Fe 3+ ion, the competitive absorption of excitation energy.